DIY 100mw TV Transmitter Printed Circuit Board (PCB)

The circuit design guiding ideology can debug without any RF instrument, its performance can not be achieved the indicators of professional equipment, but its performance should be able to meet lovers experiment, audio-visual transmission effect should not be inferior to the universal machinelevel. The transmitter is composed by two parts of the m
DIY 100mw TV Transmitter Printed Circuit Board (PCB) - schematic

odulator and RF amplifier used in the circuit all the most common is the most classic circuit. The circuit structure of the RF circuits often do not have any particular place, the key is matching circuit parameters according to different operating frequency. Example, the figure is one of the most commonly used in common emitter amplification circuit. After measurement, the circuit in a 12-channel when the gain of a dozen or so decibels, as much as 50 db below 10MHz signal amplification ability. 10MHz low frequency side, the 50 db amplifier stability work. However, when you need 12 channels of 40-50 dB of gain, certainly need three enlarged, we analyze three such amplifiers to string together what would happen. Meet the requirements put on the 12 channels, a large number, but not more than 50 db. But the three amplifier put a lot of 10MHz up to more than 150 db, which is in any case can not work. One can not work the amplifier, you can obtain the required gain it Therefore, the multi-stage RF amplifier to try to curb its lower frequency put a lot more simple method is the circuit parameters are set as shown below. The one hand, the emitter capacitance decreases to reduce the gain of the single-stage low-frequency band, but the effect is smaller, and the capacitance can not be reduced too small, otherwise the amplifier circuit status will change so that you can not control. The important step is to reduce the amount of...

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